On definite Proportions. 385 
time in a retort with a pneumatic apparatus attached to it ; 
but no gas was extricated, and that which remained in the 
apparatus was not altered. When I added a little muriatic 
acid, there was an effervescence, the mixture became yel- 
dow, and nitrogen and oxymiuriatic acid were disengaged. 
When the neutral mixture was gently evaporated, hyper- 
oxymuriate of potass crystallized in it, and the sulphate of 
ammonia effloresced, as usual, about the vessel. It appears 
therefore that these two salts do not decompose each other. 
When I attempted to prepare the hyperoxymuriate of am- 
monia according to the method of Mr. Chenevix, [ found 
that uo decomposition took place if the salts were neutral, 
but only if the acid or the alkali prevailed. Aw excess of 
‘ammonia disengages nitrogen, and the oxymuriate is 
changed into common muriate. Excess of acid disengages 
oxymuriatic acid and nitrogen. This appears therefore to 
demonstrate that neither the hyperoxymuriate of ammonia 
nor the muriatic oxide in question can exist, at least. m a 
separate form, 
CONCLUSION. 
If we compare what I have explained in this essay with 
our common experience, we seem authorised to establish 
upon these foundations the following laws of formation. 
“© In a chemical combination of two or more oxidated 
bodies, (whether it consisis of acid and acid, of acid and 
base, or of base with base,) the oxygen of the substance 
which is most abundant is a multiple by a whole number 
(1, 2, 3, 4,...) of the oxygen of the body which is least 
abundant ; and in every chemical combination beiween two | 
comlustible substances, they are present in such quantities, 
that, if the compound be orygenized, a new combination 
will be formed, which follows the same law.” 
I have already observed, that crystallized minerals must 
be formed according to this lav. And the same must be 
true of the water of crystallization of salts. Thus I have 
found that the oxygen of the water of crystallization is 
either a multiple, or, in a very few cases, a subinultiple of 
that of the base of the salt by a whole number. In the 
supercarbonate of soda, and in the muriate of ammonia, 
the water and the base contain equal quantities of oxygen. 
In the sulphate of lime, the muriate of baryta, and the 
sulphate of ammonia, the oxygen in the water of crystal- 
lization is double that of the base. Jn the sulphate of the 
protoxide of iron the water of crystallizauon contains 
Vol. 42. No. 187. Nov. 1813. Bb 7 limes, 
